Feank miller



(No Model.)

F. MILLER.

DRAWING INSTRUMENT, GALIPERS, 6w.

Patented Oct. 11, 1887.

INVENTOR $777 ATTORNEYS.

Lil

UNITE TATES FRANK MILLER, OF NE? YORK, N. Y.

DRAWING-lNSTRUMENT, CALIPERS, 84.0.

SPECIFICATION forming part of Letters Patent No. 371,469, dated October 11, 1887.

Application filed Jun) 11, 1887.

.To all whom, it may concern.-

Be it known that I, FRANK MILLER, of the city, county, and State of New York, have inventedanew and useful Improvementin Drawing-Instruments,Calipcrs, &c.,ot' which the following is a full, clear, and exact description.

My invention relates to drawing-pens, calipers, and other instruments formed withjaws, or members to be opened and closed; and the object of the invention is to provide for a very rapid and also a very slow and delicate ad justment of thejaws or members to and from each other.

' Reference is to be had to the accompanying drawings, forming a part of this specification, in which similar letters of reference indicate correspcnding parts in all the figures.

Figure 1 is a side elevation of a pair of calipers made in accordance with my invention. Fig. 2 is a similar view of a. spring bow or circle pen made in accordance with my invenvention, and Fig. 3 is a side view of a eommon drawingpen having my invention applied thereto.

a a represent the cross pivotedjaws or arms of a pair of calipers which are normally held apart by the spring b, placed between the upper ends, a a, of the saidjaws or arm Upon the arms orjaws (a (I, just below the pivot c, is placed the screwcollar f, which is annular in form, screw-threaded upon the inside, and slightly conical to conform to the slant of the outside edges of the jaws or members a a. The outer surfaces of the jaws to a are screwthreaded, as shown at d (I, so that the screwthreads of the collarf will engage with the threads d, and thus by turning the collarf Serial X0. 241,018. (No model.)

furnish very delicate means for adjusting the jaws of the instrument. In use the jaws a a will be pressed with the hand nearly to the proper adjustment. The collar f will then drop down to hold the jaws and will engage with the screw-threads (I, so that by turning the collar the jaws may be closed or permitted to expand. The bows a a of the drawingpen Bare constructed and operated upon the same plan, and also the nibs h h of the pen proper, the same being screw-threaded at the outer surface, as shown at t 1', and provided with a screw threaded nut or collar, f. The spring-jaws 7c is of the plain drawingpen O are also screw-threaded at their outer surfaces, as shown at Z l,to receive the screw-threaded collar or nut f. By squeezing the nibs h h together with the fingers the collar may be raised or lowered, furnishing, as in the other instruments, a rapid adjustment; then by turning the collar the nibs may be very delicately adj usted.

Having thus fully described my invention, I claim as new and desire to secure by Letters Patent 1 As an improvement in calipers, drawingpcns, die, the arms or jaws thereof extended to form the working points of the instrument and screw-threaded on opposite converging surfaces, in combination with an internally screw-threaded nut, f, substantially as and for the purposes set forth.

FR A NK MILLER.

Witnesses:

JOHN H. Krrounu, JOHN B. PINE. 

